The objective of this study was to examine lay health advisor (LHA) programs designed to promote health among US Latinos and the extent to which educator-only versus educator-plus-bridge programs differed in designs and outcomes achieved. Two independent coders reviewed 128 published articles on LHAs yielding information at two levels: (i) study design and participant and LHA characteristics from 61 studies that broadly compared educator-only versus educator-plus-bridge programs and (ii) implementation features and outcomes from 17 randomized controlled trials or quasi-experimental studies with outcome data. LHA programs have been widely used with Latinos in certain US regions; our findings indicate that LHAs are effective intervention agents. We identified differences between educator-only and educator-plus-bridge LHA programs, although the small number of educator-plus-bridge programs with outcome data limited comparisons. Major gaps remain in research targeting Latino subgroups other than Mexican immigrants/Mexican Americans. Sufficient research has evaluated LHA programs among Latinos on their ability to achieve health behavior and/or health status changes. In the future, more of a focus on organizational and policy changes is warranted. Questions remain about diversity in LHAs' characteristics and roles, which influence not only outcomes but also program sustainability and dissemination. © The Author 2010. Published by Oxford University Press. All rights reserved.